Calorific valueof ethane, in kJ/g if for the rxn
2C2H6 + 7O2--- 4CO2 + 6H2O + 745.6 kcal
Ans -52
How?
from the given data heat of combustion of ethane will be =-745.6 / 2 = -372.8 K cal mol-1
1K cal = 4.18J
∴-372.8 K cal = 372.8 x 4.18 =1559.7959 KJ/mol
Calorific value = heat of combustion/ gram moleculat wt. of fuel = 1559.8 / 30 = 52 KJ /g